Since prehistoric times, water conflicts have occurred as a result of a wide range of tensions and/or violence, which have rarely taken the form of traditional warfare waged over water resources alone. Instead, water has historically been a (re)source of tension and a factor in conflicts that start for other reasons. In some cases, water was used directly as a weapon through its ability to cause damage through deprivation or erosion or water resources of enemy populations and their armies. However, water conflicts, both past and present, arise for several reasons; including territorial disputes, fight for resources, and strategic advantage. The main reasons of water conflicts are usually delimitation of boundaries, waterlogging (e.g., dams and lakes), diversion of rivers flow, running water, food, and political distresses. In recent decades, the number of human casualties caused by water conflicts is more than that of natural disasters, indicating the importance of emerging trends on water wars in the world. This paper presents arguments, fights, discourses, and conflicts around water from ancient times to the present. This diachronic survey attempts to provide water governance alternatives for the current and future.

Egyptian and Greek ancient civilizations prevailed in eastern Mediterranean since prehistoric times. The Egyptian civilization is thought to have been begun in about 3150 BC until 31 BC. For the ancient Greek civilization, it started in the period of Minoan (ca. 3200 BC) up to the ending of the Hellenistic era. There are various parallels and dissimilarities between both civilizations. They co-existed during a certain timeframe (from ca. 2000 to ca. 146 BC); however, they were in two different geographic areas. Both civilizations were massive traders, subsequently, they deeply influenced the regional civilizations which have developed in that region. Various scientific and technological principles were established by both civilizations through their long histories. Water management was one of these major technologies. Accordingly, they have significantly influenced the ancient world’s hydro-technologies. In this review, a comparison of water culture issues and hydro-structures was adopted through the extended history of the ancient Egyptians and Greeks. The specific objectives of the work are to study the parallel historical cultures and hydro-technologies, assessing similarities and differences, and to analyze their progress since primitive times. The tools adopted for the research include visits to historical aeras and museums, comments, consultations, correlation and exhibitions available in the cyberspace. Review results herein showed that dams and canals were constructed in ancient Egypt to manage the flood of the Nile river and develop irrigation systems from ca. 6000 BC. In the second millennium BC, Minoans managed the flow of the streams via two dams, to protect arable land from destruction after intense rainfall and to irrigate their farms. Additional results showed that ancient Egyptians and Greeks invented many devices for lifting water for plant irrigation such as the shadouf, sakia and tympanum and pumps, of which some were already in use in Mesopotamia for irrigating small plots. The ancient Egyptians were the first who discovered the principle and the basis of coagulation (after ca. 1500 BC). They used the alum for accelerating the settlement of the particles. Additionally, the ancient Greeks developed several advanced water treatment technologies since the prehistoric times. To sum up, the study captured many similarities between two civilizations in water technologies. In addition, it confirmed the sustainability and durability of several of those hydro-technologies since they are still in use up to now in many places.

We developed a solar-driven photo-bioelectrochemical cell (s-PBEC) employing a novel anode photocatalyst material (Co₃(PO₄)₂/Mg(OH)₂) intimately coupled with electrochemically active bacteria for synergic electricity generation from wastewater. An s-PBEC was inoculated with a natural microbial community and fed with synthetic wastewater to analyze the performance of the system for electricity generation. Linear sweep voltammetry indicated an increase in power output upon light illumination of the s-PBEC after 1 h, rising from 66.0 to 91.5 mW/m². The current density in the illuminated s-PBEC exhibited a rapid increase, reaching 0.32 A/m² within 1 h, which was significantly higher than the current density in dark conditions (0.15 A/m²). Shotgun metagenomic analysis revealed a significant shift in the microbial community composition with a more diverse anodic biofilm upon illumination compared to the microbial communities in dark conditions. Three unclassified genera correlated with the enhanced current generation in illuminated s-PBEC, including Neisseriales (16.31%), Betaproteobacteria (7.37%), and Alphaproteobacteria (5.77%). This study opens avenues for further exploration and optimization of the solar-driven photo-bioelectrochemical cells, paving the way for integrative approaches for sustainable energy generation and wastewater treatment.